Laboratory Assessment of Select Methods of Corrosion Control and Repair in Reinforced Concrete Bridges

Matthew D Pritzl,Al Ghorbanpoor,Habib Tabatabai

doi:10.1155/2014/175094

Matthew D Pritzl, Al Ghorbanpoor + Show 1 more

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https://doi.org/10.1155/2014/175094

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Abstract

Fourteen reinforced concrete laboratory test specimens were used to evaluate a number of corrosion control (CoC) procedures to prolong the life of patch repairs in corrosion-damaged reinforced concrete. These specimens included layered mixed-in chlorides to represent chloride contamination due to deicing salts. All specimens were exposed to accelerated corrosion testing for three months, subjected to patch repairs with various treatments, and further subjected to additional three months of exposure to accelerated corrosion. The use of thermal sprayed zinc, galvanic embedded anodes, epoxy/polyurethane coating, acrylic coating, and an epoxy patch repair material was evaluated individually or in combination. The specimens were assessed with respect to corrosion currents (estimated mass loss), chloride ingress, surface rust staining, and corrosion of the reinforcing steel observed after dissection. Results indicated that when used in patch repair applications, the embedded galvanic anode with top surface coating, galvanic thermal sprayed zinc, and galvanic thermal sprayed zinc with surface coating were more effective in controlling corrosion than the other treatments tested.

Highlights

Penetration of chlorides from deicing salts used on bridges causes significant long-term deterioration, which requires periodic maintenance and repair [1,2,3]
The specimens were assessed with respect to corrosion currents, chloride ingress, surface rust staining, and corrosion of the reinforcing steel observed after dissection
Two (2) types of embedded discrete galvanic anodes, a humectant activated galvanic thermal sprayed zinc, a humectant activated galvanic thermal sprayed zinc with an epoxy/polyurethane coating, an embedded anode with an acrylic coating, a conventional cementitious patch repair material, and an epoxy patch repair material were chosen for evaluation

Summary

Introduction

Penetration of chlorides from deicing salts used on bridges causes significant long-term deterioration, which requires periodic maintenance and repair [1,2,3]. Patch repairs are commonly used to address this problem. Even when proper repair procedures are followed, failure of patches occurs in as little as 2–5 years [4]. The objective of this study was to assess relative performance of a number of corrosion control (CoC) procedures on patched chloride-contaminated reinforced concrete specimens tested under accelerated corrosion exposure in the laboratory. Fourteen specimens were exposed to accelerated corrosion testing for three months, subjected to patch repairs with various corrosion control treatments, and further subjected to an additional three months of exposure. The use of thermal sprayed zinc, galvanic embedded anodes, epoxy/polyurethane coating, acrylic coating, and an epoxy patch repair material was evaluated individually or in combination. The specimens were assessed with respect to corrosion currents (estimated mass loss), chloride ingress, surface rust staining, and corrosion of the reinforcing steel observed after dissection

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